# MOVEMENT

, a term often used in the same sense with Automaton. The most usual Movements for keeping time, are Clocks and Watches: the latter are such as shew the parts of time by inspection, and are portable in the pocket; the former such as publish it by sounds, and are fixed as furniture.|

Movement, in its popular use, signifies all the inner works-of a clock, watch, or other machine, that move, and by that motion carry on the design of the instrument. The Movement of a clock, or watch, is the inside; or that part which measures the time, and strikes, &c; exclusive of the frame, case, dial-plate, &c.

The parts common to both of these Movements are, the Main-spring with its appurtenances, lying in the spring box, and in the middle of it lapping about the spring-arbor, to which one end of it is fastened. A-top of the spring-arbor is the Endless screw, and its wheel; but in spring clocks this is a ratchet-wheel with its click, that stops it. That which the main-spring draws, and round which the chain or string is wrapped, is called the fusee: this is mostly taper; in large works, going with weights, it is cylindrical, and is called the barrel. The small teeth at the bottom of the fusee or barrel, which stop it in winding up, is called the Ratchet; and that which stops it when wound up, and is for that end driven up by the spring, the Gardegut. The Wheels are various: the parts of a wheel are, the Hoop or Rim; the Teeth, the Cross, and the Collet, or piece of brass soldered on the arbor or spindle on which the wheel is riveted. The little wheels, playing in the teeth of the larger, are called Pinions; and their teeth, which are 4, 5, 6, 8, &c, are called Leves; the ends of the spindle are called Pivots; and the guttured wheel, with iron spikes at bottom, in which the line of common clocks runs, the Pulley.

*Theory of Calculating the Numbers for* Movements.

1. It is first to be observed, that a wheel, divided by its pinion, shews how many turns the pinion has to one turn of the wheel.

2. That from the fusee to the balance the wheels drive the pinions, consequently the pinions run faster, or make more revolutions, chan the wheel; but it is the contrary from the great wheel to the dial-wheel.

3. That the wheels and pinions are written down either as vulgar fractions, or in the way of division in common arithmetic: sor example, a wheel of 60, moving a pinion of 5, is set down either thus 60/5, or thus 5)60, which is better. And the number of turns the pinion has in one turn of the wheel, as a quotient, thus 5) 60 (12. A whole Movement may be written as follows:

4 ) | 36 | (9 |

5 ) | 55 | ( 11 |

5 ) | 45 | ( 9 |

5 ) | 40 | ( 8 |

17 |

4. Hence, from the number of turns any pinion makes, in one turn of the wheel it works in, may be determined the number of turns a wheel or pinion has at any greater distance, viz, by multiplying the quotients together; the product being the number of turns. Thus, suppose the wheels and pinions as in the case above; the quotient 11 multiplied by 9, gives 99, the number of turns in the second pinion 5 to one turn of the wheel 55, which runs concentrical, or on the same spindle, with the pinion 5. Again, 99 multiplied by 8, gives 792, the number of turns the last pinion has to one turn of the first wheel 5. Hence we proceed to find, not only the turns, but the number of beats of the balance, in the time of those turns. For, having found the number of turns the crown-wheel has in one turn of the wheel proposed, those turns multiplied by its notches, give half the number of beats in that one turn of the wheel. Suppose, for example, the crownwheel to have 720 turns, to one of the first wheel; this number multiplied by 15, the notches in the crownwheel, produces 10800, half the number of strokes of the balance in one turn of the first wheel of 80 teeth.

The general division of a Movement is, into the clock, and watch parts.